74 Scamp Electrical

Hello everybody So here's the deal. My car wont charge. We checked the Altenator and that works just fine so then we replaced the regulator with a new one thinking that was it. We made sure that the contacts were clean as was the ground. it was working until we revved the engine and poof it wasnt charging anymore. So I honestly have no idea what to do next. I tried finding wiring diagrams but was unable to find any so here I am. If you folks know what I should do next please let me know or if you have any diagrams at all that would be a massive help since some of my wiring is missing inside the cab.
-Thanks

do you have a amp gauge had a similar situation with a 70 chally and it was simple as cleaning the connections at the back of the amp gauge, although it looked clean it just wasn't making a good connection once I cleaned it up everything worked fine then I removed the 7 ground straps the guy before me had put in everywhere he could lol
may be a long shot but thought id pass this along good luck

With key "on" confirm that you have fire at the blue wire alt field terminal and to the top blue wire terminal in the triangle connector in the flat reg. Confirm the green wire from the other alt field terminal to the "side" terminal in the triangle connector of the flat reg has continuity end to end (likely it does). seperate/check/clean the bulkhead would be my first move. alt is OK, new reg, reg is likely grounded well since you replaced it & bolted down a new one. all that is left is the above wiring checks for the open

Had a similar charging problem with a 74 Scamp.
The blue feed wire routes across the motor making several connections like the electric choke and some of the emission controls.
I'm gonna guess that the wire is compromised at one of the crimp connectors along that path.
I ran a fresh wire from the firewall pass thru to the regulator and all was solved.